Field of the Invention
This invention relates to a closure for a resilient dispensing tube or package and more particularly to a self-closing closure utilizing a diaphragm.
Self-closing closures for tubes or the like for dispensing flowable material upon the application of pressure upon the tube have been well known for many years. Continuing efforts have been made to develop such closures which are inexpensive to manufacture and yet absolutely secure for cutting off the flow of material and sealing the tube upon the relaxation of pressure on the tube.
U.S. Pat. No. 2,025,810 which issued Dec. 31, 1935 to W. Dinnes teaches a self-closing closure using a single diaphragm. In this device a planar diaphragm having an aperture therein is formed to have a rest position surrounding the top of a stem. Upon application of pressure on the tube, the diaphragm is bowed outwardly to open the valve and upon release of pressure the patent states that the diaphragm returns to its rest position. Any small amount of pressure on the tube would tend to deflect the diaphragm outwardly so that the closure is not secure. This closure unit was built to be threaded onto the neck of a tube.
Subsequently, devices were developed in which the closure became an integral part of the tube itself. In the prior art, however, these closure devices were often relatively complicated and expensive to make, have not been secure in their closure of the tube, or have had other operational disadvantages.